Tool library
All amateur observation tools
Every tool is free, runs on free public APIs without keys, and is built for civilian amateur scenarios.
Atmospheric Observation
Field tools for direct sky and atmosphere observation.
Observation Log Template Generator
Generate a printable amateur weather observation log with the fields professional networks use.
Open Atmospheric ObservationSun & Moon Angle Calculator
Compute solar altitude, azimuth, and moonlight angle for any place and time.
Open Atmospheric ObservationAtmospheric Transparency Query
Estimate local atmospheric transparency for astronomical and meteorological observation.
OpenCloud & Phenomena Identification
Identify clouds, halos, rainbows and rare optical events.
Cloud Type Identifier
Match an uploaded cloud photo against the 10 standard WMO cloud genera and read its meteorological meaning.
Open Cloud & Phenomena IdentificationRainbow Formation Probability
Compute the chance of a primary rainbow forming right now from temperature, humidity, and solar altitude.
Open Cloud & Phenomena IdentificationFog vs Haze Distinguisher
Tell meteorological fog from industrial haze using humidity, visibility, and dew-point spread.
Open Cloud & Phenomena IdentificationThunderstorm Distance Calculator
Tap when you see the flash and again when you hear the thunder. The tool reports distance in km and miles.
OpenMeteorological Calculation
Convert and compute weather quantities offline.
Temperature & Humidity Converter
Convert between °C, °F, K and between absolute, relative, and specific humidity.
Open Meteorological CalculationWind Speed & Beaufort Converter
Convert m/s, km/h, mph, knots and look up the matching Beaufort force with land-and-sea description.
Open Meteorological CalculationPressure ↔ Altitude Converter
Convert sea-level pressure to station pressure for any altitude using the barometric formula.
Open Meteorological CalculationPrecipitation Conversion Tool
Convert rainfall depth (mm) to volume (L/m²), rate (mm/h), and accumulated totals.
OpenOutdoor Weather Prediction
Plan amateur outings with risk-aware weather context.
Popular Science Query
Niche atmospheric science references and lookups.
Rare Phenomena Calendar
Lookup historical occurrence probability for halos, coronae, mirages, noctilucent clouds and more.
Open Popular Science QueryLocal Microclimate Query
Query community-scale micro-temperature, micro-wind, and micro-humidity using free Open-Meteo data.
Open Popular Science QuerySolar Term Weather Patterns
Summarize historical meteorological tendencies of each of the 24 solar terms.
Open Popular Science QueryPolar Day & Night Reference
Reference high-latitude polar day and polar night meteorological behavior.
Open Popular Science QueryMeteorological Terminology Simplifier
Translate professional meteorological terms into plain civilian language.
Open Popular Science QueryWeather Map Legend Explainer
Explain professional icons and legends used on surface and upper-air weather maps.
Open Popular Science QueryHistorical Weather Lookup
Query daily historical weather for any location using the free Open-Meteo archive API.
Open